Dot matrix printing, sometimes called impact matrix printing, is the process of computer printing from a collection of dot matrix data to a device, which can be one of: Impact dot matrix printers non-impact dot matrix printers, such as inkjet, thermal, or laser printers. Impact dot matrix printing uses a print head that moves back-and-forth, or in an up-and-down motion, on the page and prints by impact, striking an ink-soaked cloth ribbon against the paper, much like the print mechanism on a typewriter. However, unlike a typewriter or daisy wheel printer, letters are drawn out of a dot matrix, thus, varied fonts and arbitrary graphics can be produced; these printers can print on multi-part forms. The alternative to dot matrix printing is sometimes known as a letter-quality printer or a line printer which use formed type elements that impact a sheet of paper; the perceived quality of dot matrix printers depends on the vertical and horizontal resolution and the ability of the printer to overlap adjacent dots.

For impact dot matrix printers 9 pin and 24 pin were common, this specified the number of pins in a specific vertically aligned space. For 24 pin where the horizontal movement could overlap dots a "near letter quality" was specified, this produced visually superior output at the cost of speed. Impact Dot matrix printing is a type of computer printing which uses a print head that moves back-and-forth, or in an up-and-down motion, on the page and prints by impact, striking an ink-soaked cloth ribbon against the paper, much like the print mechanism on a typewriter. However, unlike a typewriter or daisy wheel printer, letters are drawn out of a dot matrix, thus, varied fonts and arbitrary graphics can be produced. Although nearly all inkjet and laser printers print spaced dots rather than continuous lines or characters, it is not customary to call them dot matrix printers; each dot is produced by a tiny metal rod called a "wire" or "pin", driven forward by the power of a tiny electromagnet or solenoid, either directly or through small levers.

Facing the ribbon and the paper is a small guide plate named ribbon mask holder or protector, sometimes called butterfly for its typical shape. It is pierced with holes to serve as guides for the pins; the plate may be made of an artificial jewel such as sapphire or ruby. The portion of the printer that contains the pin is called the print head; when running the printer, it prints one line of text at a time. There are two approaches to achieve this: The common serial dot matrix printers use a horizontally moving print head; the print head can be thought of featuring a single vertical column of seven or more pins the height of a character box. In reality, the pins are arranged in up to four vertically or/and horizontally displaced columns in order to increase the dot density and print speed through interleaving without causing the pins to jam. Thereby, up to 48 pins can be used to form the characters of a line while the print head moves horizontally. In a different configuration, so called line dot matrix printers use a fixed print head as wide as the paper path utilizing a horizontal line of thousands of pins for printing.

Sometimes two horizontally displaced rows are used to improve the effective dot density through interleaving. While still line-oriented, these printers for the professional heavy-duty market print a whole line at once while the paper moves forward below the print head; the printing speed of serial dot matrix printers with moving. In contrast to this, line matrix printers are capable of printing much more than 1000 cps, resulting in a throughput of up to 800 pages/hour; because the printing involves mechanical pressure, both of these types of printers can create carbon copies and carbonless copies. These machines can be durable; when they do wear out, it is due to ink invading the guide plate of the print head, causing grit to adhere to it. With tungsten blocks and titanium pawls, the printing becomes too unclear to read, a common problem when users failed to maintain the printer with regular cleaning as outlined in most user manuals. A variation on the dot matrix printer was the cross hammer dot printer, patented by Seikosha in 1982.

The smooth cylindrical roller of a conventional printer was replaced by a fluted cylinder. The print head was a simple hammer, with a vertical projecting edge, operated by an electromagnet. Where the vertical edge of the hammer intersected the horizontal flute of the cylinder, compressing the paper and ribbon between them, a single dot was marked on the paper. Characters were built up of multiple dots. In 1925, Rudolf Hell invented the Hellschreiber, an early facsimile-like dot matrix-based teletypewriter device, patented in 1929. Between 1952 and 1954 Fritz Karl Preikschat filed five patent applications for his teletype writer 7 stylus 35 dot matrix aka PKT printer, a dot matrix teletypewriter built between 1954 and 1956 in Germany. Like the earlier Hellschreiber, it still used electromechanical means of coding and decoding, but it used a start-stop method rather than synchronous transmission for communication. In 1956, while he was employed at Telefonbau und Normalzeit GmbH, the device was introduced to the Deutsche Bundespost, which did not show interest.

When Preikschat emigrated into the US in 1957 he sold the rights to utilize the appli

Roberto Longhi was an Italian academic, art historian and curator. The main subjects of his studies were Piero della Francesca. Longhi was born in December 1890 in Alba in Piedmont, his parents were from Emilia. He studied with Pietro Toesca, in Turin, Adolfo Venturi in Rome; the latter made him book reviews editor of the journal L'Arte in 1914. Between 1913 and 1917, Longhi an essayist, published text in L'Arte and La Voce on Mattia Preti, Piero della Francesca, Orazio Borgianni and Orazio Gentileschi. Over the course of his career Longhi developed a fascination with his followers, his book Quesiti caravaggeschi, was followed by Ultimi studi caravaggeschi. In 1951, Longhi curated a ground-breaking exhibition on Caravaggio at the Royal Palace in Milan, Mostra di Caravaggio e dei Caravaggeschi. In 1968 he authored a monograph on the artist. Whilst establishing himself as a notable Caravaggio scholar, Longhi retained a lively interest in Piero della Francesca, editing a monograph in 1928, representing him as the leading painter of the Quattrocento.

Longhi believed Piero della Francesca played a decisive role in the development of Venetian painting. This monograph, which Kenneth Clark opined could hardly be improved upon, established itself as a classic of art-historical literature. Between 1920 and 1922, Longhi made a Grand Tour of Europe, he never visited Russia, nor some American collections, like the Kress Collection of the National Gallery, Washington. However, his first-hand viewing of many works, like those in the Borghese Gallery in Rome, led to the rediscovery of many lost masterpieces such as two panels of a Giotto altarpiece. Longhi rekindled interest in a large number of followers of Caravaggio, such as Hendrick ter Brugghen and some painters from Ferrara, his book Officina Ferrarese still stands as an exemplary study. Along with the publication of the Officina, Longhi started his academic career, first as Professor at Bologna University, in Florence. In 1950, Longhi co-founded and edited with Anna Banti Paragone, a bi-monthly magazine on art and literature still running to these days.

Longhi curated a number of exhibitions, including Mostra della pittura bolognese del Trecento. Longhi died on June 3, 1970, is buried at Cimitero degli Allori in Florence. Longhi, Roberto. Piero della Francesca. Rome: Valori Plastici. Longhi, Roberto. Officina ferrarese. Edizioni d'Italia. Longhi, Roberto. Viatico per cinque secoli di pittura veneziana. Florence: Sansoni. Longhi, Roberto. Mostra del Caravaggio e dei caravaggeschi Catalogo. Florence: Sansoni. Longhi, Roberto. Edizione delle opere complete di Roberto Longhi. 14 vols. Florence: Sansoni. Longhi, Roberto. Correggio: the Frescoes in San Giovanni Evangelista in Parma. New York: H. N. Abrams. Longhi, Roberto. Me pinxit e quesiti caravaggeschi, 1928-1934. Florence: Sansoni. Roberto Longhi Biography in Archivio della scuola Romana

The 2007 Nextel Open and Nextel All-Star Challenge was a professional auto race held on Saturday, May 19, 2007, at Lowe's Motor Speedway in Concord, North Carolina, a suburb of Charlotte. Native Carolinian and former NBA superstar Michael Jordan was the grand marshal of the event; the race is unique to its "All-Star Game" format, much like those in the other North American major "stick and ball" sports. Only race winners in the 2006 and the first eleven races of the 2007 seasons, plus former Winston/Nextel Cup Champions and All-Star event winners from the past decade automatically qualify for the main event. A description on how the race was reformatted for the 2007 running can be found here; the race awards no points as it is an exhibition race, meaning drivers can take greater risks than they would do in a regular event. In addition, on restarts of the race after caution flags, the cars line up in a double file restart, akin to the start of a regulation race. Qualifying for this event is abnormal to the standards of NASCAR.

Those entered for the main event take three timed qualifying laps, but they must take a required pit stop for four tires after either the first or second lap, coming in at the pit road speed, but come out at full throttle. This puts a premium on the pit crew teams to be fast like regular pit stops, to out the field, pit box No. 22 is used for all qualifiers. Infractions will incur time penalties. Starting in 2007, the selection of the pit boxes used by teams were made after the annual Pit Crew Challenge event to be held three days earlier at Charlotte Bobcats Arena, won by the Ryan Newman No. 12 team. In the qualifying, Matt Kenseth won the pole. Kevin Harvick was bumper-to-bumper with Jimmie Johnson coming to the start/finish line to win the race. All other drivers or teams that are in the Nextel Cup Top 50 owners or drivers points that do not automatically qualify for the All-Star Challenge are entered into a 40-lap, two-half event called the Nextel Open. Only the top two drivers, plus one additional driver on the lead lap, voted in by fans on the world wide web via Sprint/Nextel's web site, their customers and attendees of the race, join the elite field.

Standard qualifying rules applied for those in this event, which saw Carl Edwards win "P-1", edging fellow Roush-Fenway teammate David Ragan. The Nextel Open was won by Martin Truex, Jr.. Johnny Sauter finished second. Before the All-Star Challenge, a new preliminary race was held between Nextel Cup crew chiefs—the Kobalt Tools Crew Chief Race; the race comprised eighteen crew chiefs driving small Legends Thunder Roadster cars on the quarter-mile oval in front of the main track's grandstand, was televised in the United States on Speed. NASCAR on ESPN color commentator and former crew chief, Andy Petree won the main event, earning a $10,000 donation for any charity of his choice; the charities he decided to donate the race winnings to were Motor Racing Outreach and Mud Creek Baptist Church. The following drivers qualified after they won at least one race in the 2006 or 2007 seasons, in order of their qualifying win: Jimmie Johnson - 2006 Daytona 500 Matt Kenseth - 2006 Auto Club 500 Kasey Kahne - 2006 Golden Corral 500 Kurt Busch - 2006 Food City 500 Tony Stewart - 2006 DirecTV 500 Kevin Harvick - 2006 Subway Fresh 500 Dale Earnhardt, Jr. - 2006 Crown Royal 400 Greg Biffle - 2006 Dodge Charger 500 Denny Hamlin - 2006 Pocono 500 Jeff Gordon - 2006 Dodge/Save Mart 350 Kyle Busch - 2006 Lenox Industrial Tools 300 Jeff Burton - 2006 Dover 400 Brian Vickers - 2006 UAW Ford 500 The following drivers qualified as a result of driving a car that won a race in 2006 with a different driver: Casey Mears - No. 25 car won the 2006 UAW Ford 500The following drivers qualified as a result of being a former Nextel Cup champion: Jeff Gordon Dale Jarrett Bobby Labonte Tony Stewart Matt Kenseth Kurt Busch Jimmie Johnson The following drivers qualified as a result of being a former winner of the Nextel All-Star Challenge: Jeff Gordon Mark Martin 1999 winner was Terry Labonte, who retired after the 2006 season and did not compete Dale Earnhardt, Jr. Ryan Newman Jimmie Johnson Matt Kenseth The following drivers qualified via the Nextel Open: Martin Truex Jr.

Johnny Sauter Also qualifying, the 2007 Fan Vote Winner: Kenny Wallace Martin Truex, Jr. won the Nextel Open, the first win for him of any kind in a Nextel Cup race. Johnny Sauter edged out Carl Edwards for the second transfer spot on offer in this race; the 40-lap race was stopped four times due to caution, including a 10-car incident halfway through lap 1 in which, among other things, the hoods of the cars driven by David Gilliland and Juan Pablo Montoya collided into each other. As mentioned above, Kenny Wallace won the fan vote a credit to a large get out the vote campaign mounted by Speed Channel, where he works as an analyst. Kevin Harvick passed Jeff Burton at the start of the fourth and final segment and never looked back to win the main event race for the first time in his career. Harvick won $1,031,539 for the